Stationary contact system for vibratory switches



June l, 1937. F. o. HARTMAN 2,082,493

STATIONARY CONTACT SYSTEM FOR VIBRATORY SWITCHES 2 Sheets-Sheet l FiledMay 24, 1955 I Hl! ummm June 1, 1937.

F. O. HARTMAN STATIONARY CONTACT SYSTEM FOR VIBRATORY SWITCHES Filed May24, 1933 2 Sheets-Sheet 2 J7 5 O @E INVENTOR.

Patented June l, 1937 UNITED STATES lPATENT OFFICE STATIONARY CONTACTSYSTEM FCR VIBRATORY SWITCHES Application May 24, 193'3, serial No.672,730 claims. (ci. zoo- 166) My invention relates broadlyto apparatusfor converting low voltage direct current into high voltage alternatingcurrent of a character suitable for neon tube advertising sign lightingand 5 more particularly to a stationary contact system employed in suchapparatus.

One of the objects of my invention is to provide a stationary Contactsystem in a construction of converter for changing low voltage direct l0current (for example, 110 volts) into high voltage alternating current(for example, 5000 volts) suitable for neon tube lighting for operatingadvertising signs and the like in districts where only direct currentpower supply is available.

Another object of my invention is to provide a. construction of astationary contact system in a vibratory switch for use in connectionwith a suitable transformer in supplying alternating current from adirect current source.

Still another object of my invention is to provide a construction ofstationary contact systems for use in electromagnetically controlledswitching apparatus and having means for adjusting the movement of apivoted armature for insuring continuous vibratory operation thereofwith respect to the stationary contact systems.

A further object of my invention is to provide a construction ofadjustment mechanism for the stationary contacts of a vibratory switchfor insuring successive opening and closing of a pair of coactingelectrical circuits at a relatively high continuous rate of speed.

Other and further objects of my invention reside in the construction ofcontacts for a vibratory switching system as set forth more fully in thespecication hereinafter following by reference to the accompanyingdrawings, in which:

Figure 1 is a central vertical longitudinal section through a vibratoryswitch embodying the stationary contact system of my invention; Fig. 2is a transverse sectional View taken on line 2-2 of Fig. l; Fig. 3 is atop plan view of the vibratory switch, showing the contact system of myinvention; Figs. 4 and 5 are horizontal sectional views taken throughthe vibratory switch on lines 4-4 and 5 5, respectively, of Fig. 1; andFigs. 6 and '7 are detailed plan views of the vibratory springs employedin the stationary contact system of my invention.

My invention is directed to an inexpensive construction of contacts fora vibratory switch for use in a converter which will enable neon tubessuch as used in advertising signs to be operated in districts where onlydirect current power supply is available. To light a neon tube requireshigh voltage alternating current from 1200 to 15,000 volts or more,depending on the number of feet of tubing to be lighted. Wherealternating current is available, this is accomplished by 5 means of atransformer delivering the proper voltage from the secondary winding. Ina number of cities, however, there is no alternating current availablein certain districts, and in such districts it is necessary to use arotary converter 10 when it is desired to install a neon sign. The costof this rotary converter makes it almost prohibitive in the case of thesmall show-window sign. The device of my invention is intended for usein connection with these small show- 15 window signs in direct currentdistricts.' The y apparatus of my invention is extremely simple in itsconstruction and is rugged in its design and inexpensive inconstruction.

Another practical use for the vibratory switch structure of my inventionis in a converter system for producing volt alternating current from alow voltage direct current supply such as an automobile storage batteryor house lighting system (32 volts). 25

Referring to the drawings, the casing I 1 encloses a. vibratorymechanism and has the side portions thereof extending telescopicallyover a base portion 22 as shown more clearly in Fig. 2. Screw memberslla.- are passed through casing 30 I1 and engage with base 22 forsecuring the casing I'l in position with respect to the base 22. Thebase 22 is apertured at 22a and over this aperture there is secured theplate of insulation material 23. Any suitable method of securing 35plate 23 with respect to the base 22 may be employed, such as the rivetsshown at 23a. The insulated plate 23 carries a set of prongs 24 whichprovide connectors for the electromagnetic means within the casing l1.The interior of the base 22 40 is lined by means of a resilient shockabsorbing pad 2l which iits Within-the up-turned side walls of the base22 and provides a cushion for the vibratory mechanism within casing Iland substantially prevents the transmission of undesired 45 vibrationsor sound from the casing Il.

The interior of casing I1 is lined with resilient material similar tothe lining 2l of base 22. I have shown the lining for the interior ofcasing YIl in the form of sheets of material 28 forming 50 asubstantially sound-proof covering for the top and side walls of thecasing I1. The resilient sheets of material 28 adjacent opposite sidesof the vibratory mechanism also serve to absorb the shock of themechanical vibration for the rea- 55 son that the side trames of thevibratory mecha.- nism are in close contact with the resilient sheets ofmaterial 2l which line the interior side walls of the casing i1.

The vibratory mechanism is mounted in a frame structure constituted bythe frame members 2l and Il) which are erected vertically within thecasing l1. Frame members 29 and l0 provide supports for the laminatedcore structure ll which is disposed centrally between frame members 2land I5 by means of spacer members 22 and 3l and coacting screw members32a and 83a and central screw member lla which extends through thelaminated core structure 2|. By reason o! the assembly of the spacermembers I2 and 3l on each side oi the laminated core structure li bymeans or screw device lla, the assembly of the frame members 2l and Il.with respect to spacer members 32 and II, is greatly simplied. as tramemembers 2Q and I0 can be readily secured to spacer members l2 and 33 bymeans of screws 32a and 33a in the manner shown. The laminated corestructure 3i has a central pole piece lib and opposite pole pieces Sicand lid. On pole pieces lic and lid, I provide electro-magnetic windingsI4 and I5 well insulated from the pole pieces llc and Jld, respectively.'I'he windings I4 and 35 have their ends brought out independently andsecured to terminal strips mounted on insulated panels carried by framemembers 29 and 20. as shown. 'I'hat is to say. frame member 29 carries ahorizontally disposed insulated panel Il secured thereto by suitablemeans such as rivets. Panel carries terminal members 34a and 35a whichprovide terminal connections for one end o! each oi the windings 34 andI5 respectively. 0n the opposite i'rame member I0, I provide ahorizontally dis posed strip member 21 secured to frame member I. bysuitable means such as rivets and carrying terminal members to which theother ends of the respective windings I4 and 35 are connected.

The central pole piece Sib of laminated core structure Il is aperturedtor the passage of a screw device Ile which provides connecting meansfor sleeve members 25 and 29 extending on opposite sides of the corestructure and intermediate the windings 24 and 35. Screws extend throughtrame members 25 and 3l respectively and engage sleeves 2l and I9thereby rigidly centering the intermediate pole SIb between tramemembers 25 and Il. Above the pole pieces 2lb, llc and Sid. I provide apivot for the vibratory amature 4l. The vibratory armature 40 isconstructed from a strip oi' magnetic material which is centrallyextruding in opposite directions to provide an axially extending recess40a through which the pin member 4I extends. The pin member 4| isJournaled at opposite ends in insulated bearings formed by insulatedplates 42 and 4l and suitable means such as rivets 42a and 43a toopposite sides of the vertically disposed frame members 25 and 30. Byreason of the arrangement of the insulated plates 42 and 43 whichreceive the opposite ends of pin 4I, the amature 4l is electricallyinsulated from the frame members 29 and I0 at all times. In order toprovide for a good electrical connection to the vibratory armature 40, apositive bonded connection is made through lead 4 electrically connectedto the pin 4i and extending through a slot 20a in frame member 3l to aposition beneath screw Ila by which connection is made to the framemember 30. A connection is taken from frame member l0 at screw 22athrough lead 45 to one of the prongs 24. The opposite ends of armature40 carry contact members which I have shown at 41 and 48. One end oi thearmature 40 is weighted, as shown at 49 which thereby tends to maintaincontact 48 initially in electrical connection with the stationarycontact 50 upon starting of the apparatus. The stationary contact 5i.located at the opposite end of the apparatus, is disposed in alignmentwith movable contact 41 for the establishment of successive connectiontherewith. 'I'he method oi' mounting the stationary contacts isextremely important as control of the rate of operation of the apparatusmay be made by adjustment of the stationary contacts. The supports forthe stationary contacts are mounted on in-turned upper portions of framemembers 29 and 30. A stationary plate 52 is mounted by means of screw52a on the in-turned upper edge portions of frame members 29 and IB. Thetwo stationary contact systems are insulated from each other and mountedon the insulated plate 52.

The insulated plate 52 provides a support for all of the several membersconstituting the sta tionary contact system of my invention. The twostationary contact systems employed are identi cal in their constructionand arrangement oi parts so that one set of reference characters hasbeen employed to designate corresponding members in the sets of partsconstituting the contact systems. That is to say, a plate member 53 issupported directly upon the upper surface of the insulated plate 52. Aparallel plate 54 is arranged immediately above plate 53 and is spacedtherefrom by spacing member 55 which forms an integral part of theconnecting lug by which connection is established with the stationarycontact forming part of the contact system. The connectors 55a leadingfrom the lugs forming part of the spacer member 55 connect with theterminal plates which are carried on the insulated strip 31. Thesuperimposed plate members 5l and 54 are secured with respect to theinsulated plate 52 by means of screws 56 which extend therethrough asshown. Screws 55 pass through the resilient reed 51, the threaded spacer59 and the spring reed 50 which carries the stationary contact 50. Nuts52 serve to secure the spring reed 50 in position on screws 56. It willbe observed that the end of spring reed 51 is slotted and apertured at5l, whereas spring reec. 80 contains an intermediate slot and aperture6|. The T-head 56 of set screw 65 is engaged in the apertures and slots58 and 8| in the spring reeds 51 and 60, respectively which are alignedone with the other to permit the passage of T-head 56 of the set screwl5 which is adjustable in screw threaded apertures formed in platemembers 53 and 54. In order to insure the permanent setting of thestationary contact in a given range of angular displacement, I provide abinding screw G4 which extends through screw threaded and alignedapertures in plate members 53 and 54 and is free to enter an aperture52h in insulated plate 52. By tightening the binding screw 84 after theset screw 55 has been adjusted .to a desired position, a permanentposition oi the set screw may be maintained. An independent adjustmentis provided for spring reed 51 through adjustment screw 52 which extendsthrough plate members 53 and 54 and bears against spring reed 51 forpermitting spring reed 51 to be angularly shifted within limitsdetermined by the position of spring reed 60 and the lower face ofinsulated plate 52.

lil)

mosaics 3 The frequency of vibration of the armature lli is primarilydetermined by its own inertia and by the natural frequency of the springreeds 51 and to which the contacts 50 and 5i are secured. However byoperation of the several adjusting screws which I have described, thenatural frequency of these reeds can be altered. The frequency at whichthe switching operation is performed is directly controllable byadjustment of screw 63 and set screw 65, which adjustment when initiallyselected is set by means of binding screw 64.

The casing l1 is metallic and serves as an electromagnetic shield forpreventing radiation of undesired interference which might prove asource of annoyance in the circuits of radio broadcast receivers used inclose proximity to th vibratory switch.

I have illustrated in the drawings the method of acoustically shieldingthe vibratory apparatus for preventing the vibratory mechanism frombecoming a source of annoyance by emitting a continuous buzzing sound.The shielding material shown at 21 in the base 22 and forming the lining28 in the casing I1, provides a tight enclosure around all four sides ofthe vibratory mechanism. The sound deadening material may be spongerubber, felt, or other suitable material having sound absorbing anddeadening qualities. The sound absorbing material at the sides of themechanism fits closely around the apparatus thereby assisting in thevertical mounting of the vibratory unit at the same time that the soundproofing qualities of the lining material are utilized.

The vibratory switch employing the contact system of my invention hasproven to be highly practical in manufacture, production and use.Converters are very convenient for the inexpensive operation of neontube signs in districts where only direct current is available. From thestandard low voltage direct current circuits, as for example, volts, Iam able to obtain by use of my apparatus, voltages within such ranges as3,000 to 15,000 volts suitable for neon tube lighting. v

Systems employing my invention make it possible for the standardalternating current midget radio receiver tobe placed directly in anautomobile and connected to the storage battery for operation.

Although I have shown the apparatus of my invention in one of itspreferred embodiments, I desire that it be understood that modificationsand changes may be made in the construction and assembly of the partsand I intend no limitations upon my invention other than are imposed bythe scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. In a vibratory switch, a stationary contact system including a pairof spring strips, an adjustable guide engaging one of said spring stripsfor regulating the position of both said spring strips, a tensionadjusting screw adjustable against the other of said spring strips, andlocking means common to said adjustable guide and said tension adjustingscrew.

2. In a vibratory switch, a panel of insulation material, a stationarycontact system mounted on said panel, said stationary contact systemincluding a pair of parallel disposed supporting strips mounted on topof said panel in spaced relation. a pair of resilient strips mountedbeneath said panel in spaced relation, a contact carried by the lowerface of one of said resilient strips, a screw-threaded adjusting deviceextending through said parallel disposed supporting strips and throughsaid panel and engaging said one of said resilient strips for limitingthe angular displacement thereof, and a binding screw extending throughsaid supporting strips for locking said supporting strips in bindingrelation with respect to said screw-threaded adjusting device.

3. In a vibratory switch, a panel of insulation material, a stationarycontact system mounted on said panel. said stationary contact systemincluding a pairv of parallel disposed supporting strips mounted on topof said panel in spaced relation, a pair of resilient strips mountedbeneath said panel in spaced relation, a contact carried by the lowerface of one of said resilient strips, a screw-threaded adjusting deviceextending through said parallel disposed supporting strips and throughsaid panel and engaging said one of said resilient strips for limitingthe angular displacement thereof, an independent adjusting deviceextending through said supporting strips and engaging the other of saidresilient strips for controlling the effective tension thereof, and abinding screw extending through said supporting strips for locking saidsupporting strips in binding relation with respect to both saidadjusting devices.

4. A stationary contact system for vibratory switches, comprising aresilient member having a contact member at one end thereof and beingfixed at the other end thereof, means cooperative with said resilientmember adjacent the free end thereof for determining the position ofsaid contact member, means bearing on said resilient member foradjusting the effective degree of resiliency in said resilient member,and locking means common to both said means for locking both said meansin the selected positions.

5. In an electrical vibratory switch, a stationary contact systemincluding a pair of resilient strips mounted in spaced relation, acontact carried by one of said strips, means engaging the aforesaidstrip for adjusting the position of said contact, means including theother of said strip members for adjusting the effective tension of theaforesaid strip member, and means common to both said adjusting meansfor locking both said means in the adjusted position.

FRANK O. HARTMAN.

